Corrosion testing apparatus



I. KIRSHENBAUM ETAL CORROSION TESTING APPARATUS Nov. 28, 1950 Filed Nov.28, 1945 JNVENTOR. \SlDOR KIRSHENBAUM. BY DAVID A. M CAULAY.

ATTORNEY.

Patented Nov. 28, 1950 CORROSION TESTING APPARATUS Isidor Kirshenbaum,New York, N. Y., and David Allan McCaulay, Chicago, Ill., assignors tothe United States of America as represented by the United States AtomicEnergy Commission Application November 28, 1945, Serial No. 631,415

2 Claims.

1 The present invention relates to apparatus for simultaneously treatina material such as a metal sample with a corrosive fluid and its vaporand more particularly, to an apparatus for exposing the metal sample tothe concurrent action of the corrosive fluid and vapor in a manner suchthat the actual effect of a volatile corrosive agent on the metalmembers of a distillation tower may be closely approximated.

The invention is particularly suitable for predetermining a choice ofmetallic packings, for example Stedman packingssuitable for use indistillation towers in which fluorides are circulated, and for moreaccurately predicting the useful lifetime of the component metal partsof the installation.

In order to be satisfactory for the purpose indicated, such a testingapparatus must closely approximate actual fiuid and vapor pressure andflow as well as temperature conditions of the commercial installation.

It is, therefore, an object of this invention to provide an apparatusfor testing the efiect of a continuous flow of corrosive fluid and vaporon a metal sample.

A further object is to provide a testing apparatus of the type indicatedwherein the fluid and vapor pressure, flow, and temperature conditionsmay be controlled.

Other objects of the invention will be in part a invention.

Referring to the figure, the corrosion testing apparatus consists of aglass test-tube like cylinder ll] having a top or head 12 joined theretoby a ground glass joint M to seal out the atmosphere. Secured in thehead !2 is a cold finger condenser I 6 including an inlet l8 and outlet26 for the introduction and discharge of a condenser coolant. A pressureregulating means 22 is also connected by a line 24 to the top !2 andprovides means for regulatin and maintaining a desired pressure in thecylindrical chamber H3.

Below the cold finger condenser Hi there are formed in the cylinder IE3several indentations 26 that support a glass sleeve 28 in which issecured a metal sample 38 that is to be tested. Resting above the sample35 on the sleeve 28 is a second glass sleeve 32 that contains glasshelices at for distributing evenly over the metal sample 3!! a hotcorrosive liquid 36. The liquid 35 is introduced as a combination liquidand vapor into cylindric chamber II! by a means for feeding the liquidin pulses comprising a reservoir 38 through a connecting tube 40 at apoint slightly above the lower end of the condenser 16. The vaporcondenses on the condenser 56 and the liquid 36 drops onto the helices34, which distribute the liquid evenly over the metal sample 35.Thereafter, the liquid is collected in the bottom of the cylinder Illand is gravity fed by a glass conduit 42 into the reservoir 38. Theconduit 42 is connected to the chamber H) at a point below the normallevel of the liquid 36 in the bottom of the chamber and enters thereservoir 38 above the normal liquid level point which is determined bythe level to which the tube Ml extends into the reservoir. The tube 42is bent into a U- shaped trap 44 which prevents the passage of thevapors from the reservoir into the lower end of the chamber It).

The reservoir is individually heated by an external electrical heatingunit 45 the heat output of which is controlled by control 48. The liquidin the chamber H3 is similarly heated by .a heating unit 5!! controlledby a rheostat 52 for the purpose of enveloping the test sample all in ahot corrosive vapor of the liquid 35.

The method of operation of the testing appara tus heretofore describedis as follows: The metal packing sample 30 is placed in the sleeve 28and set on the indentations 25 in the chamber it. The sleeve 32containing the helices 34 isplaced on top of the sleeve 28 and the head!2 containing the condenser I 6 is fitted into the chamber H3. A coolantsuch as water is circulated through connections l8 and 2%! in thecondenser. Thereafter,

the liquid in the reservoir is heated by the unit 46 and forced throughthe tube til into the chamber It! where any vapor carried over iscondensed on the condenser IS. The liquid 35 is distributed over themetal sample 353 by the helices, as heretofore described, and iscollected in the bottom of the chamber it! from which it is siphonedthrough tube 42 into the reservoir 38. The liquid 36 in the chamber It!is also partially vaporized by the heating unit 5b to therebysimultaneously treat the sample 39 with both vapor and hot liquid. Thepressure in the chamber It is controlled by the pressure regulatingmeans 22 and may be regulated to simulate the pressure conditions thatare found in a particular commercial installation. In addition to visualinspection of the sample before and after treatment in the testingapparatus, physical changes may be determined by changes in weight ofthe sample and by suitable chemical tests.

From the above description it is apparent that the method of the presentinvention for testing the corroding properties of a metal sample iscapable of accurately approximating the vari ous corrosive conditionsfound in a variety of closed commercial installations such as, forexample, distillation towers, and that the illustrated and describedtesting apparatus compris ing a preferred embodiment of the invention isa compact and efficient structure for achieving the several objects setforth above.

It is, of course, to be understood thatthe invention is not limited tothe specific construction shown in the drawing; Other types of heatingunits may be substituted for those shown. Similarly, alternative typesof condensers and distributing helices may be substituted for thosedescribed and the apparatus may be constructlower portion thereof,indentations centrally of said tube, a first sleeve supported on saidindentations and arranged to support a sampleout of contact withcorrosive liquid in the lower portion of thetube, asecond sleevesupportable by said first sleeve and containing a plurality of glasshelices, afinger condenserin the upper portion of said tube, thelowermost portion of the condenser being above the second sleeve, ameans for feeding the liquid in pulses-including a reservoir arranged tocontain a vaporizable corrosive liquid, a first conduit connecting saidreservoir with the lower portion of the tube whereby liquid in said tubemay flow'into said reservoir, a second conduit connecting'the saidreservoir with the tube adjacent the condenser and above the secondsleeve whereby the sample is periodically flushed with liquidcorrosivematerial from the reservoir, heating means for the reservoirand heating means for the tube whereby the sample is continuouslyexposedto corrosive vapors and is periodically flushed with corrosiveliquid by action of the feedin means.

2. Apparatus for testing a sample for corrosion resistance comprising aclosed tube arranged to contain a vaporizable corrosive liquid in thelower portion thereof, indentation centrally of said tube, a firstsleeve supported on said indentations and arranged to support a sampleout of contact with corrosiveliquid in, the lower portion of the tube, asecond sleeve supportable by said first sleeve and containing aplurality of glass helices, a finger condenser in the upper portion ofsaid tube, the lowermost portion of the condenser being above the secondsleeve, pressure regulating means in communication with the upperportion of said tube and arranged to control pressure in said tube, ameans for feedin a liquid'in pulses including a reservoir arranged tocontain a vaporizable corrosive liquid, a first conduit connecting saidreservoir with the lower portion of said tube whereby liquid in saidtube-may flow into said reservoir, a second conduit connecting saidreservoir with the tube adjacent the-condenser and above the secondsleeve whereby the sample isperiodically flushed with liquid corrosivematerialfrom: the reservoir, heating means for the reservoi and heatingmeans for the tube whereby the sample is continuously exposed tocorrosive vapors and is periodically flushed with corrosive liquid byaction of the pulsed feeding means.

ISIDOR' KIRSHENBAUM; DAVID ALLAN McCAULAY.

REFERENCES CITED The following references are of record-in the file ofthis patent:

UNITED STATES PATENTS,

OTHER REFERENCES Qthmer, Industrial and Engineering Chemistry (Anal.Ed.) vol. 1 (1929), page 209, I

Ace General Catalogue 40 (Oct. 1940), page 126 (7790), and page 129(7840) Gas Analysis and Testing of Gaseous Materials, Altieri (N. Y.C.), 1945, pages 352 ,and;447.

